Field of the Invention
The invention relates to a pipe bender for preparing long U-shaped pipes, and more particularly to a pipe bender for preparing long U-shaped pipes capable of processing two kinds of pipes having different diameters.
Description of the Related Art
As a compact heat exchanger, the finned tube heat exchanger is widely used in the refrigeration industry. With the development of technology in the air conditioning and the refrigeration industry, and the implementation of the environmental regulations, more and more strict requirements have been imposed on the heat transfer performance of the heat exchanger in order to make up for the low performance of the refrigerant. The structure of the heat exchanger (the type of the heat exchange tube and the fin tube) and the forming process of the heat exchanger are important factors that affect the heat transfer performance and have great significance in improving the integral heat transfer performance. The forming process of the heat exchanger mainly includes three kinds: bending to form a U-shaped pipe; expanding mechanical tubes to achieve the connection of the tube and the fin; and bending pipe bundles to form an L-shaped or a G-shaped heat exchanger.
Currently, when the long U-shaped pipes are bent by a pipe bender, a calibration device, a feeding device, and a bending device must be chosen correspondingly based on the diameter of the pipes. However, if the pipes to be processed are two kinds having different diameters, some components of the calibration device, the feeding device, and the bending device must be replaced, which is very inconvenient and troublesome.